HIV-1 does not replicate in resting T cells. Instead, the viral genome is randomly integrated into the cellular DNA, where it can remain dormant indefinitely. In activated T cells, replication of HIV-1 is stimulated by the binding of cellular transcription factors to the promoter region of the V~NS (the HIV-1 LTR). One of the cellular transcription factors known to be involved in the upregulation of HIV-1 provirus replication in activated T cells is NF-KB. The ablation of the two NF-KB binding sites within HIV-1 LTR impairs viral replication in activated T cells. NF-KB is also an important transcription factor in the process of T cell activation; binding of NF-KB to the IL-2 promoter region is essential to the production of this pro-survival cytokine during the T cell activation response. Nuclear translocation of NF-kB can be stimulated by signaling through CD3/CD28 costimulation, and the serine/threonine kinase PKCB plays an obligatory role in the activation of NF-KB by CD3/CD28 signaling. Preliminary experiments indicate that PKC theta selectively activates the HIV-1 LTR in a NF-kB-dependant fashion, and pharmamlogical inhibition of PKC theta prevents activation of the HIV-1 promoter. Therefore, it is possible that PKC theta plays a crucial role in mediating HIV-1 replication after T cell activation. In order to determine whether PKC theta is required for HIV-1 replication in activated T cells, we plan to block the expression or function of PKC theta in T cells and examine whether these manipulations inhibit HIV-1 replication. In Aim 1, we will ablate PKC theta expression using various strategies and examine the effects of these manipulations on the activii of the HIV-1 LTR fused to a luciferase reporter. In Aim 2, we will examine the effects of inhibition of PKC theta function or expression on HIV-1 replication in T cells. In Aim 3, we will address a possible role for PKC theta in T cell hyperactkation mediated by the viral protein Nef. These experiments will determine whether PKC theta is required for HIV-1 replication in activated T cells. and mav result in new therawtic aowoaches for the treatment of HIV-1 infection. HIV-1 does not replicate in resting T cells. Instead, the viral genome is randomly integrated into the cellular DNA,